With Tuesday’s downpour, rainfall in Mumbai crosses annual average mark

Mumbai recorded 331.4mm rain, which is the highest 24-hour August rain in a decade

Extremely heavy rain brought the city to a standstill on Tuesday.(Pramod Thakur/HT)

With more than a month for the monsoon season to end, the city has already surpassed its annual average rainfall after Tuesday’s heavy downpour.

As against an annual rainfall average of 2258mm, Mumbai received 2334mm between the beginning of monsoon (June 12) till 8.30am on Wednesday. Moreover, Tuesday’s rainfall resulted in the city recording its highest monthly rainfall (941.1mm) for August since 2011. In August 2010, Mumbai had recorded 1036.5mm, which is the highest August total for the decade.

Between 8.30am Tuesday and 8.30am Wednesday, the Santacruz weather station, representative of the suburbs and Mumbai, recorded 331.4mm rain, which is the highest 24-hour August rain in a decade. During the same time Colaba recorded 111mm rain. Before Tuesday, the highest 24-hour August rain for the decade was recorded on August 29, 2011, when the city received 232.6mm rainfall.

The all-time high 24-hour rain in August was recorded on August 23, 1997 at 346.2mm. The city was just 15mm short of achieving the highest 24-hour August rain levels over the past two decades.

After ‘extremely heavy’ rain brought the city to a standstill on Tuesday, there was sunshine on Wednesday morning, followed by reduced rainfall intensity during the afternoon. Between 8.30am and 5.30pm Wednesday, Santacruz and Colaba recorded 7.6mm and 6.4mm rain.

Torrential showers with 171.6mm rain, was recorded in Mumbai over just a span of three hours (from 2.30pm to 5.30pm) and 315.8 mm was recorded over 12 hours starting 8.30am on Tuesday. Waterlogging left lakhs stranded as trains and buses were not functioning for several hours.

The weather bureau said there was a drastic reduction in rainfall activity and levels were expected to reduce further. “The low pressure area (weather system) responsible for the heavy rain over Mumbai has shifted over Gujarat and parts of the Arabian Sea. We expect isolated heavy rain in some parts of north Konkan but rainfall activity in Mumbai is expected to be minimal. Only light showers are now expected,” said Mrutunjay Mohapatra, head of climate services, India Meteorological Department (IMD).

The amount of rainfall recorded over 24 hours was almost three times less than received during the deluge on July 26, 2005 when it rained 944mm within 24 hours. However, on Tuesday, rain in the city had surpassed the 24 hour record just over a span of nine hours during the day itself.

The weather bureau said that Tuesday’s 315.8mm in 12 hours till 8.30 pm was the second highest since July 26, 2005 deluge. “After tallying our data, we observed that rainfall levels, recorded during 15 hours on Tuesday, are the second highest for a 24- hour period since July 26-27, 2005,” said KS Hosalikar, deputy director general, western region, from India Meteorological Department.